\[3m,\ \ m^{2} + 2,\ \ m + 4.\]
\[m^{2} + 2 = \frac{3m + m + 4}{2}\text{\ \ }\]
\[m^{2} + 2 = \frac{4m + 4}{2}\ \]
\[m^{2} + 2 = 2m + 2\]
\[m^{2} + 2 - 2m - 2 = 0\]
\[m^{2} - 2m = 0\]
\[m(m - 2) = 0\]
\[m = 0;\ \ m = 2.\]
\[при\ m = 0 \Longrightarrow 0;2;4.\]
\[при\ m = 2 \Longrightarrow 6;6;6.\]